小怡分享之Java图书管理系统

前言：

🌈✨前面小怡给大家分享了抽象类和接口，今天小怡给大家分享用Java实现图书管理系统。

1.功能

不同的用户看到的菜单是不一样的，我们分为两个用户身份，管理员和普通用户。

2.知识点

数据类型、变量、数组、方法、类和对象、继承和多态、封装、抽象类和接口。今天要把上述知识点全部用起来。

3. 实现框架

首先我们要建立一个新的文件，在文件内建立三个包，分别命名为book（书籍）、user（使用者）、ioperation（操作）。

3.1 book包

因为是图书管理系统，我们先写和图书相关的内容。book包里有三个类，分别是Book（图书）、BookList（书架）、Main（主功能）。

Book类：

public class Book {
    private String name;//书名
    private String author;//作者
    private int price;//价格
    private String type;//书籍类型
    private boolean isBorrowed;//是否借出

    public Book(String name, String author, int price, String type) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.type = type;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public boolean isBorrowed() {
        return isBorrowed;
    }

    public void setBorrowed(boolean borrowed) {
        isBorrowed = borrowed;
    }

    @Override
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                ", isBorrowed=" + isBorrowed +
                '}';
    }
}

BookList类：

public class BookList {
    private Book[] books=new Book[10];
    private int usedSize;//有效的数据个数【实际放的书的个数】
    public BookList(){
        books[0]=new Book("三国演义","罗贯中",30,"小说");
        books[1]=new Book("西游记","吴承恩",40,"小说");
        books[2]=new Book("红楼梦","曹雪芹",50,"小说");
        this.usedSize=3;
    }
}

Main类（这个得在其他类写好了才来写）：

public class Main {
    public static User login(){
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入您的姓名：   ");
        String name=scanner.nextLine();
        System.out.println("请输入您的身份，1.管理员  2.普通用户：   ");
        int choice=scanner.nextInt();
        if (choice==1){
            return new Librarian(name);
        }else if(choice==2){
            return new Reader(name);
        }else{
            return null;
        }
    }
    public static void main(String[] args) {
        BookList bookList=new BookList();
        User user=login();
        user.menu();
        int choice=user.menu();
        user.doIoperation(choice,bookList);
    }
}

3.2 user包

user包里有三个类，分别是：Librarian（图书管理员）、Reader（读者）、User（使用者）。

User类：

public abstract class User {
    protected String name;
    protected IOPeration[] ioPerations;
    public User(String name){
        this.name=name;
    }
    public abstract int menu();
    public void  doIoperation(int choice, BookList bookList){
        ioPerations[choice].work(bookList);
    }
}

Librarian类：

public class Librarian extends User{
    public Librarian(String name) {
        super(name);
        this.ioPerations=new IOPeration[]{
        new ExitOperation(),
        new FindOperation(),
        new AddOperation(),
        new DelOperation(),
        new ShowOperation(),
        };
    }

    public int menu(){
        System.out.println("欢迎"+name+"来到图书管理系统");
        System.out.println("*******管理员菜单*******");
        System.out.println("1.查找图书");
        System.out.println("2.新增图书");
        System.out.println("3.删除图书");
        System.out.println("4.显示图书");
        System.out.println("0.退出系统");
        System.out.println("***********************");
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入您的操作：   ");
        int choice=scanner.nextInt();
        return choice;
    }
}

Reader类：

public class Reader extends User{
    public Reader(String name) {
        super(name);
        this.ioPerations=new IOPeration[]{new ExitOperation(),
                new FindOperation(),
                new BorrowOperation(),
                new ReturnOperation()
        };
    }
    public int menu(){
        System.out.println("欢迎"+name+"来到图书管理系统");
        System.out.println("*******读者菜单*******");
        System.out.println("1.查找图书");
        System.out.println("2.借阅图书");
        System.out.println("3.归还图书");
        System.out.println("0.退出系统");
        System.out.println("*********************");
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入您的操作：   ");
        int choice=scanner.nextInt();
        return choice;
    }
}

3.3 ioperation 包

现在书的属性和用户的属性的包和类以及完成差不多，由于想要实现的功能和操作基本上是针对图书的，我们可以创一个包ioperation，还有命名一个接口IOPeration。里卖弄有七个类，一个接口。

AddOperation类（新增图书）：

public class AddOperation implements IOPeration{
        public void work(BookList bookList){
            System.out.println("新增图书……");
        }
}

BorrowOperation类（借阅图书）：

public class BorrowOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("借阅图书……");
    }
}

DelOperation类（删除图书）：

public class DelOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("删除图书……");
    }
}

ExitOperation类（退出系统）：

public class ExitOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("退出系统……");
    }
}

FindOperation类（查找图书）：

public class FindOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("查找图书……");
    }
}

IOPeration接口：

public interface IOPeration {
    void work(BookList bookList);
}

ReturnOperation类（归还图书）：

public class ReturnOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("归还图书……");
    }
}

ShowOperation类（显示图书）：

public class ShowOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("显示图书……");
    }
}

4.实现功能

4.1 退出系统

退出系统比较容易实现

System.exit(0);

4.2 显示图书

显示图书其实就需要遍历数组，我们使用一个for循环就行。

int currentSize=bookList.getUsedSize();
        for(int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            System.out.println(book);
        }

在BookList里面也要加上get和set。

 public Book getBooks(int pos) {
        return books[pos];
    }

    public void setBooks(int pos,Book book) {
        this.books[pos] = book;
    }

    public int getUsedSize() {
        return usedSize;
    }

    public void setUsedSize(int usedSize) {
        this.usedSize = usedSize;
    }

4.3 查找图书

这里用到了for循环和equals

 Scanner scanner=new Scanner(System.in);
    System.out.printf("请输入您的书名：  ");
    String name=scanner.nextLine();
        int currentSize=bookList.getUsedSize();
        for (int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                System.out.println("找到了这本书");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有你要找的这本书");

4.4 新增图书

要先输入各种成员变量构建对象，再判断数组满没满，然后放到数组的最后一个位置，used++。

public void work(BookList bookList){
            System.out.println("新增图书……");
            int currentSize=bookList.getUsedSize();
            if(currentSize==bookList.getBooks().length){
                System.out.println("书架满了，不能放了");
                return;
            }
            Scanner scanner=new Scanner(System.in);
            System.out.println("请输入书名：   ");
            String name=scanner.nextLine();
            System.out.println("请输入作者：   ");
            String author=scanner.nextLine();
            System.out.println("请输入价格：   ");
            int price=scanner.nextInt();
            System.out.println("请输入书的类型：   ");
            String type=scanner.nextLine();
            Book newbook=new Book(name,author,price,type);
            for (int i=0;i<currentSize;i++){
                Book book=bookList.getBooks(i);
                if(book.getName().equals(name)){
                    System.out.println("有这本书，不能增加");
                    System.out.println(book);
                    return;
                }
            }
            bookList.setBooks(currentSize,newbook);
            bookList.setUsedSize(currentSize+1);
            System.out.println("新增图书成功");
        }

4.5 借阅图书

借阅图书和查找图书有很大一部分是相似的。

int currentSize=bookList.getUsedSize();
        for (int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                if (book.isBorrowed()==true){
                    System.out.println("这本书已经被借出了");
                    return;
                }
                book.setBorrowed(true);
                System.out.println("借阅成功");
                return;
            }
        }
        System.out.println("没有你要借阅的这本书");

4.6 归还图书

借阅和归还的整体逻辑是修改状态。

System.out.println("归还图书……");
        Scanner scanner=new Scanner(System.in);
        System.out.printf("请输入您归还的书名：  ");
        String name=scanner.nextLine();
        int currentSize=bookList.getUsedSize();
        for (int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                if (book.isBorrowed()==true){
                    book.setBorrowed(false);
                    System.out.println("归还成功");
                    return;
                }
                
            }
        }
        System.out.println("没有你要归还的图书");

4.7 删除图书

Scanner scanner=new Scanner(System.in);
        System.out.print("请输入您删除的书名：  ");
        String name=scanner.nextLine();
        int currentSize=bookList.getUsedSize();
        int pos=-1;
        int i=0;
        for (;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                System.out.println("找到了这本书");
                pos=i;
                break;
            }
        }
        if (i==currentSize){
            System.out.println("没有你要删除的书");
            return;
        }
        //开始删除
        for (int j=pos;j<currentSize-1;j++){
            Book book=bookList.getBooks(j+1);
            bookList.setBooks(j,book);
        }
        bookList.setUsedSize(currentSize-1);

5.运行案例

6.源代码

Book类：

package book;
public class Book {
    private String name;//书名
    private String author;//作者
    private int price;//价格
    private String type;//书籍类型
    private boolean isBorrowed;//是否借出

    public Book(String name, String author, int price, String type) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.type = type;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public boolean isBorrowed() {
        return isBorrowed;
    }

    public void setBorrowed(boolean borrowed) {
        isBorrowed = borrowed;
    }

    @Override
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                ", isBorrowed=" + ((isBorrowed==true) ?"已借出":"未借出")+
                '}';
    }
}

BookList类：

package book;
public class BookList {
    private Book[] books=new Book[10];
    private int usedSize;//有效的数据个数【实际放的书的个数】
    public BookList(){
        books[0]=new Book("三国演义","罗贯中",30,"小说");
        books[1]=new Book("西游记","吴承恩",40,"小说");
        books[2]=new Book("红楼梦","曹雪芹",50,"小说");
        this.usedSize=3;
    }

    public Book getBooks(int pos) {
        return books[pos];
    }

    public void setBooks(int pos,Book book) {
        this.books[pos] = book;
    }

    public int getUsedSize() {
        return usedSize;
    }

    public void setUsedSize(int usedSize) {
        this.usedSize = usedSize;
    }
    public Book[] getBooks(){
        return books;
    }
}

Main类：

package book;

import ioperation.IOPeration;
import user.Librarian;
import user.Reader;
import user.User;

import java.util.Scanner;

public class Main {
    public static User login(){
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入您的姓名：   ");
        String name=scanner.nextLine();
        System.out.println("请输入您的身份，1.管理员  2.普通用户：   ");
        int choice=scanner.nextInt();
        if (choice==1){
            return new Librarian(name);
        }else if(choice==2){
            return new Reader(name);
        }else{
            return null;
        }
    }
    public static void main(String[] args) {
        BookList bookList=new BookList();
        User user=login();
        user.menu();
        int choice=user.menu();
        user.doIoperation(choice,bookList);
    }
}

AddOperation类：

package ioperation;

import book.Book;
import book.BookList;

import java.util.Scanner;

public class AddOperation implements IOPeration{
        public void work(BookList bookList){
            System.out.println("新增图书……");
            int currentSize=bookList.getUsedSize();
            if(currentSize==bookList.getBooks().length){
                System.out.println("书架满了，不能放了");
                return;
            }
            Scanner scanner=new Scanner(System.in);
            System.out.println("请输入书名：   ");
            String name=scanner.nextLine();
            System.out.println("请输入作者：   ");
            String author=scanner.nextLine();
            System.out.println("请输入书的类型：   ");
            String type=scanner.nextLine();
            System.out.println("请输入价格：   ");
            int price=scanner.nextInt();

            Book newbook=new Book(name,author,price,type);
            for (int i=0;i<currentSize;i++){
                Book book=bookList.getBooks(i);
                if(book.getName().equals(name)){
                    System.out.println("有这本书，不能增加");
                    System.out.println(book);
                    return;
                }
            }
            bookList.setBooks(currentSize,newbook);
            bookList.setUsedSize(currentSize+1);
            System.out.println("新增图书成功");
        }
}

BorrowOperation类：

package ioperation;

import book.Book;
import book.BookList;

import java.util.Scanner;

public class BorrowOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("借阅图书……");
        Scanner scanner=new Scanner(System.in);
        System.out.printf("请输入您借阅的书名：  ");
        String name=scanner.nextLine();
        int currentSize=bookList.getUsedSize();
        for (int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                if (book.isBorrowed()==true){
                    System.out.println("这本书已经被借出了");
                    return;
                }
                book.setBorrowed(true);
                System.out.println("借阅成功");
                return;
            }
        }
        System.out.println("没有你要借阅的这本书");
    }
}

DelOperation类：

package ioperation;

import book.Book;
import book.BookList;

import java.util.Scanner;
public class DelOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("删除图书……");
        Scanner scanner=new Scanner(System.in);
        System.out.print("请输入您删除的书名：  ");
        String name=scanner.nextLine();
        int currentSize=bookList.getUsedSize();
        int pos=-1;
        int i=0;
        for (;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                System.out.println("找到了这本书");
                pos=i;
                break;
            }
        }
        if (i==currentSize){
            System.out.println("没有你要删除的书");
            return;
        }
        //开始删除
        for (int j=pos;j<currentSize-1;j++){
            Book book=bookList.getBooks(j+1);
            bookList.setBooks(j,book);
        }
        bookList.setUsedSize(currentSize-1);
    }
}

ExitOperation类：

package ioperation;

import book.BookList;
public class ExitOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("退出系统……");
        System.exit(0);
    }
}

FindOperation类：

package ioperation;

import book.Book;
import book.BookList;

import java.util.Scanner;
public class FindOperation implements IOPeration{
    public void work(BookList bookList){
    System.out.println("查找图书……");
    Scanner scanner=new Scanner(System.in);
    System.out.printf("请输入您的书名：  ");
    String name=scanner.nextLine();
        int currentSize=bookList.getUsedSize();
        for (int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                System.out.println("找到了这本书");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有你要找的这本书");
    }
}

IOPeration接口：

package ioperation;

import book.BookList;

public interface IOPeration {
    void work(BookList bookList);
}

ReturnOperation类：

package ioperation;

import book.Book;
import book.BookList;

import java.util.Scanner;

public class ReturnOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("归还图书……");
        Scanner scanner=new Scanner(System.in);
        System.out.printf("请输入您归还的书名：  ");
        String name=scanner.nextLine();
        int currentSize=bookList.getUsedSize();
        for (int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            if(book.getName().equals(name)){
                if (book.isBorrowed()==true){
                    book.setBorrowed(false);
                    System.out.println("归还成功");
                    return;
                }

            }
        }
        System.out.println("没有你要归还的图书");
    }
}

ShowOperation类：

package ioperation;

import book.Book;
import book.BookList;

public class ShowOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("显示图书……");
        int currentSize=bookList.getUsedSize();
        for(int i=0;i<currentSize;i++){
            Book book=bookList.getBooks(i);
            System.out.println(book);
        }
    }
}

Librarian类：

package user;

import ioperation.*;

import java.util.Scanner;

public class Librarian extends User{
    public Librarian(String name) {
        super(name);
        this.ioPerations=new IOPeration[]{
        new ExitOperation(),
        new FindOperation(),
        new AddOperation(),
        new DelOperation(),
        new ShowOperation(),
        };
    }

    public int menu(){
        System.out.println("欢迎"+name+"来到图书管理系统");
        System.out.println("*******管理员菜单*******");
        System.out.println("1.查找图书");
        System.out.println("2.新增图书");
        System.out.println("3.删除图书");
        System.out.println("4.显示图书");
        System.out.println("0.退出系统");
        System.out.println("***********************");
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入您的操作：   ");
        int choice=scanner.nextInt();
        return choice;
    }
}

Reader类：

package user;

import ioperation.*;

import java.util.Scanner;

public class Reader extends User{
    public Reader(String name) {
        super(name);
        this.ioPerations=new IOPeration[]{new ExitOperation(),
                new FindOperation(),
                new BorrowOperation(),
                new ReturnOperation()
        };
    }
    public int menu(){
        System.out.println("欢迎"+name+"来到图书管理系统");
        System.out.println("*******读者菜单*******");
        System.out.println("1.查找图书");
        System.out.println("2.借阅图书");
        System.out.println("3.归还图书");
        System.out.println("0.退出系统");
        System.out.println("*********************");
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入您的操作：   ");
        int choice=scanner.nextInt();
        return choice;
    }
}

User类：

package user;

import book.BookList;
import ioperation.IOPeration;

public abstract class User {
    protected String name;
    protected IOPeration[] ioPerations;
    public User(String name){
        this.name=name;
    }
    public abstract int menu();
    public void  doIoperation(int choice, BookList bookList){
        ioPerations[choice].work(bookList);
    }
}

🌈✨今天的分享到这里结束啦，小怡和大家一起进步一起学习。“没有人不喜欢聪慧而努力的人，所以，所有的老板都会青睐酸梅汤型员工。想当这样的员工不容易，重在时间的积累。快捷得不到成绩，只有在历练中才能收获一种有价值的甜”。